This is one of the most debatable topics I feel.
There was a time when people used to respect each other and truly stand for one another.
As the time evolves, things have drastically changed. So many relationships nowadays just break because they get bored easily.
The only thing constant In life is changes. and that is the reason behind while most of those things you explain occured. Mindset can be manipulated and also social media has broken alot of relationship.
Manipulation is caused as a result of listening to wrong
people advice or listening to social media influencers which can change your mind in an instant because they have influence which makes people believe so much in them.